• Title/Summary/Keyword: Contamination of Surface

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옥외에서 사용되는 배전급 폴리머 현수애자의 오손특성에 관한 연구

  • Lee, Byung-Sung;Han, Sang-Ok
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.50 no.7
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    • pp.340-345
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    • 2001
  • Because they have superior insulating properties and lower in price than their ceramic equivalents, polymeric insulators have been used in outdoor insulators. But polymeric insulators mainly using in an heavy contamination area of outdoor could be easily attached to contaminants such as salt and by-products of industrial processes. To understand its effect on contaminants adhered to these insulators, we dismounted polymeric insulators adhered contaminant in the field, and evaluated its electrical characteristics, CA, and ESDD. We also manufactured slurry mixed by some kaolin and salt for the artificial contamination test and measured the degree of contaminant, AC leakage current for these contaminated samples. Consequently, the adhered contaminants to its surface is likely to be affected the performance of insulation.

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Occupational Exposure to Antineoplastic Drugs: Identification of Job Categories Potentially Exposed throughout the Hospital Medication System

  • Hon, Chun-Yip;Teschke, Kay;Chua, Prescillia;Venners, Scott;Nakashima, Lynne
    • Safety and Health at Work
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    • v.2 no.3
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    • pp.273-281
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    • 2011
  • Objectives: Studies examining healthcare workers' exposure to antineoplastic drugs have focused on the drug preparation or drug administration areas. However, such an approach has probably underestimated the overall exposure risk as the drugs need to be delivered to the facility, transported internally and then disposed. The objective of this study is to determine whether drug contamination occurs throughout a facility and, simultaneously, to identify those job categories that are potentially exposed. Methods: This was a multi-site study based in Vancouver, British Columbia. Interviews were conducted to determine the departments where the drugs travel. Subsequent site observations were performed to ascertain those surfaces which frequently came into contact with antineoplastic drugs and to determine the job categories which are likely to contact these surfaces. Wipe samples were collected to quantify surface contamination. Results: Surface contamination was found in all six stages of the hospital medication system. Job categories consistently found to be at risk of exposure were nurses, pharmacists, pharmacy technicians, and pharmacy receivers. Up to 11 job categories per site may be at risk of exposure at some point during the hospital medication system. Conclusion: We found drug contamination on select surfaces at every stage of the medication system, which indicates the existence of an exposure potential throughout the facility. Our results suggest that a broader range of workers are potentially exposed than has been previously examined. These results will allow us to develop a more inclusive exposure assessment encompassing all healthcare workers that are at risk throughout the hospital medication system.

A Summary of Radiation Accidents in Atomic Energy Activities of Korea (우리나라의 원자력 연구 개발에 수반된 방사선 사고)

  • 이현덕;하정우
    • Nuclear Engineering and Technology
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    • v.2 no.2
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    • pp.97-106
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    • 1970
  • Radiation accidents which occured in the A.E.R.I. during last ten years are described (table 1). It seemed to the authors that some of these accidents were considered to be hazardous to man body and associated installations. This report deals with the following four major accidents involving body contamination incidents that our health physicists have been experienced. 1. Over-exposures (up to 130 rem) to the total body due to the mismanipulation in the Cobalt-60 gamma irradiation facility. 2. Floor surface contamination (up to 13 mrad/hr) and its spread out due to the mishandling of radioiodine contained in the bottle. 3. Body surface contamination and 0.36 uCi radioactivity accumulated in the thyroid gland of a worker due to the inhalation of gaseous iodine-131. 4. A void capsule due to the leakage out of the radium therapeutic source (3mg\ulcorner) These accidents were treated by definitely prompt action to protect the workers and associated installations from any radiation hazards and every possible efforts were made to confine the spread of radioactive contamination as small area as possible by means of elaborate decontamination work and monitoring.

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Reduction of Electron Contamination in Photon Beam by electron Filter in 6MV Linear Accelerator (6MV 선형가속기에서 Al/Cu에 관한 여과판 사용시 전자오염 감소에 관한 연구)

  • Lee, Cheol-Su
    • The Journal of Korean Society for Radiation Therapy
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    • v.8 no.1
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    • pp.41-54
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    • 1996
  • The secondary electrons developed by interaction between primary beam and a tray mounted for blocks in Megavoltage irradiation result in excess soft radiation dose to the surface layer. To reduce this electron contamination, electron filters have been used to be attached under a tray. Various filters with Cu and Al plates in six different thickness and Cu/Al combined plates in 3 different thickness were tested to measure the reduction rate of secondary electron contamination to the surface layer. The measurement to find optimal filter was performed on 6MV linear accelerator in $10 cm{\times}10 cm$ field size and fixed 78.5cm source to measurement points distance from surface to maximum build up point in 2mm intervals. The result was analyzed as the ratio of measured doses with using filters, to standard doses of measured open beam. The result of this study was fellowing : 1. The contaminated low energy radiation were mainly produced by blocking tray. 2. The surface absorbed dose was slowly increased by increasing irradiation field size but rapidly increased at field size above $15cm{\times}15cm$. 3. Al plate upto 2.5mm thickness used as a filter was found to be inadequate due to the failure of reduction of the surface absorbed dose below doses of the under surface upto the maximal build up. Cu 0.5mm plate and Cu 0.28mm/A1 1.5mm compound plate were found to be optimal filters. 4. By using these 2 filters, the absorbed dose to the surface were effectively reduced $5.5\%$ in field size $4cm{\times}4cm,\;11.3\%$ in field size $10cm{\times}10cm,\;22.3\%$ in field size $25cm{\times}25cm$. 5. In field size $10cm{\times}10cm$, the absorbed dose to the surface of irradiation was reduced by setting TSD 20cm at least,. but effective and enough dose reduction could be achieved by setting TSD 30cm as 2 optimal filters used. 6. More surface dose absorbed at TSD less than 7.4cm with a tray and filters together indicated that soft radiation was also developed by filters. 7. The variation of PDD by the different size of irradiation field was minimal as 2 optimal filters used. There was also not different in variation of PDD according to using any of two different filters. 8. PDD was not effected either by various TSD or by using the different filter among two.

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A Model for Evaluating the Radioactive Contamination in the Urban Environment (도시환경에서 방사성물질의 오염평가 모델개발)

  • Hwang, Won-Tae;Kim, Eun-Han;Jeong, Hyo-Joon;Suh, Kyung-Suk;Han, Moon-Hee
    • Journal of Radiation Protection and Research
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    • v.30 no.3
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    • pp.99-105
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    • 2005
  • A model for evaluating radioactive contamination in the urban environment, named METRO-K, was developed as a basic step for accident consequence analysis in case of an accidental release. The three kind of radionuclides $(^{137}Cs,\;^{106}Ru,\;^{131}I)$ and the different chemical forms of iodine (particulate, organic and elemental forms) are considered in the model. The radioactive concentrations are evaluated for the five types of surface (roof, paved road, wall, lawn/soil, tree) as a function of time. Using the model, the contaminative impacts of the surfaces were intensively investigated with respect to with and without precipitation during the measurement periods of radionuclides in air. In addition, a practical application study was conducted using $^{137}Cs$ concentration in air and precipitation measured in an European country at the Chernobyl accident. As a result precipitation was an influential factor in surface contamination. The degree of contamination was strongly dependent on the types of radionuclide and surface. Precipitation was more influential in contamination of $^{137}Cs$ than that of $^{131}I$ (elemental form).

Assessment of drinking water quality and its health impact on local community in coastal belt Karachi

  • Samo, Saleem Raza;Channa, Raja Siraj Ahmed;Mukwana, Kishan Chand
    • Advances in environmental research
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    • v.6 no.3
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    • pp.203-216
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    • 2017
  • For survival of human beings clean water is an essential commodity whereas contamination in drinking water threatens to mankind. The main cause of water contamination is social and development activities of human being along with increasing population. The community in the study area has acute shortage of drinking water along with about 40 to 60% has no access to safe drinking water. This study indicates drinking water quality of two major sources of coastal belt of Karachi one is supplied by Karachi Water & Sewerage Board (KWSB) as tap water and the other through groundwater. The physicochemical analysis was carried out by following the standard methods for checking the quality of drinking water. The analyzed results showed that the quality of groundwater was unfit as potable water. The most critical situation was observed as high level of contamination followed by high turbidity and increased salinity levels. TDS in surface water were found 12% above and TDS in groundwater was 20% below the National Drinking Water Quality Standards (NDWQS) of Pakistan as well as the permissible WHO drinking water quality guidelines.